The reaction of anhydro-4-hydroxy-1,3-oxazolium hydroxide (3) with acetylenic dipolarophiles gave 1,3-dipolar cycloadducts (4) along with furans (5). On heating above 80°C, most cycloadducts decomposed to the corresponding furans under release of methyl isocyanate.
脱
水-
4-羟基-1,3-
恶唑鎓氢氧化物 (3) 与炔属偶极亲和体的反应产生 1,3-偶极环加合物 (4) 和
呋喃 (5)。加热到 80°C 以上时,大多数环加合物在
异氰酸甲酯释放下分解为相应的
呋喃。